index.php

<?php

/**
 * Main template file
 * 
 * @package Aquila
 */
get_header();

?>

<div id="primary" class="content">
    <div id="main" class="site-main mt-5" role="main">
        <?php
        if (have_posts()) :
        ?>
            <div class="container">
                <?php
                if (is_home() && !is_front_page()) {
                ?>
                    <header class="mb-5">
                        <h1 class="page-title secreen-reader-text">
                            <?php single_post_title(); ?>
                        </h1>
                    </header>
                <?php
                }
                ?>

                <div class="row">
                    <?php
                    $index = 0;
                    $no_of_columns = 3;

                    while (have_posts()) : the_post();
                        // Start the loop.
                        if (0 === $index % $no_of_columns) {
                    ?>
                            <div class="col-lg-4 col-md-6 col-sm-12">
                            <?php
                        }

                        get_template_part('template-parts/content');

                        $index++;

                        if (0 !== $index && 0 === $index % $no_of_columns) {
                            ?>
                            </div>
                    <?php
                        }

                    endwhile;
                    ?>
                </div>
            </div>
        <?php
        else :
            get_template_part('template-parts/content-none');
        endif;

        ?>
    </div>

</div>

<?php

get_footer();